Conformal shielding process using process gases

ABSTRACT

In one embodiment, a meta-module having circuitry for two or more modules is formed on a substrate, which is preferably a laminated substrate. The circuitry for the different modules is initially formed on the single meta-module. Each module will have one or more component areas in which the circuitry is formed. A metallic structure is formed on or in the substrate for each component area to be shielded. A single body, such as an overmold body, is then formed over all of the modules on the meta-module. At least a portion of the metallic structure for each component area to be shielded is then exposed through the body by a cutting, drilling, or like operation. Next, an electromagnetic shield material is applied to the exterior surface of the body of each of the component areas to be shielded and in contact with the exposed portion of the metallic structures.

This application is a continuation of U.S. patent application Ser. No.11/952,634, entitled “CONFORMAL SHIELDING PROCESS USING PROCESS GASES,”filed Dec. 7, 2007, which claims priority to U.S. provisional patentapplications 60/946,453, entitled “CONFORMAL SHIELDING,” filed Jun. 27,2007, and 60/978,006, entitled “CONFORMAL ELECTROMAGNETIC INTERFERENCESHIELDING,” filed Oct. 5, 2007, the disclosures of which areincorporated herein by reference in their entireties.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to U.S. patent application Ser. No.11/199,319, entitled “METHOD OF MAKING A CONFORMAL ELECTROMAGNETICINTERFERENCE SHIELD,” filed Aug. 8, 2005, now U.S. Pat. No. 7,451,539;U.S. patent application Ser. No. 11/435,913, entitled “SUB-MODULECONFORMAL ELECTROMAGNETIC INTERFERENCE SHIELD,” filed May 17, 2006; U.S.patent application Ser. No. 11/952,484, entitled “FIELD BARRIERSTRUCTURES WITHIN A CONFORMAL SHIELD,” filed Dec. 7, 2007; U.S. patentapplication Ser. No. 11/952,513, entitled “ISOLATED CONFORMALSHIELDING,” filed Dec. 7, 2007; U.S. patent application Ser. No.11/952,545, entitled “CONFORMAL SHIELDING EMPLOYING SEGMENT BUILDUP,”filed Dec. 7, 2007; U.S. patent application Ser. No. 11/952,592,entitled “CONFORMAL SHIELDING PROCESS USING FLUSH STRUCTURES,” filedDec. 7, 2007; U.S. patent application Ser. No. 11/952,617, entitled“HEAT SINK FORMED WITH CONFORMAL SHIELD,” filed Dec. 7, 2007; U.S.patent application Ser. No. 11/952,670, entitled “BOTTOM SIDE SUPPORTSTRUCTURE FOR CONFORMAL SHIELDING PROCESS,” filed Dec. 7, 2007; and U.S.patent application Ser. No. 11/952,690, “BACKSIDE SEAL FOR CONFORMALSHIELDING PROCESS,” filed Dec. 7, 2007; the disclosures of which areincorporated herein by reference in their entireties. This applicationis also related to U.S. patent application Ser. No. 11/768,014, entitled“INTEGRATED SHIELD FOR A NO-LEAD SEMICONDUCTOR DEVICE PACKAGE,” filedJun. 25, 2007; U.S. patent application Ser. No. 11/952,634, entitled“CONFORMAL SHIELDING PROCESS USING PROCESS GASES,” filed Dec. 7, 2007;U.S. patent application number 12/766,347, entitled “CONFORMAL SHIELDINGEMPLOYING SEGMENT BUILDUP,” filed Apr. 23, 2010; U.S. patent applicationSer. No. 12/797,381, entitled “INTEGRATED POWER AMPLIFIER ANDTRANSCEIVER,” filed Jun. 9, 2010; U.S. patent application number12/913,364, entitled “BACKSIDE SEAL FOR CONFORMAL SHIELDING PROCESS,”filed Oct. 27, 2010; and U.S. patent application Ser. No. 13/117,284,entitled “CONFORMAL SHIELDING EMPLOYING SEGMENT BUILDUP,” filed May 27,2011.

FIELD OF THE INVENTION

The present invention relates to providing shielding for semiconductormodules, wherein the shielding is integrated with the semiconductormodules.

BACKGROUND OF THE INVENTION

Electronic components have become ubiquitous in modern society. Theelectronics industry routinely announces accelerated clocking speeds,higher transmission frequencies, and smaller integrated circuit modules.While the benefits of these devices are myriad, smaller electroniccomponents that operate at higher frequencies also create problems.Higher operating frequencies mean shorter wavelengths, where shorterconductive elements within electronic circuitry may act as antennas tounintentionally broadcast electromagnetic emissions throughout theelectromagnetic spectrum. If the signal strengths of the emissions arehigh enough, the emissions may interfere with the operation of anelectronic component subjected to the emissions. Further, the FederalCommunications Commission (FCC) and other regulatory agencies regulatethese emissions, and as such, these emissions must be kept withinregulatory requirements.

One way to reduce emissions is to form a shield about the modules thateither cause emissions or are sensitive to emissions. Typically, ashield is formed from a grounded conductive structure that covers amodule or a portion thereof. When emissions from electronic componentswithin the shield strike the interior surface of the shield, theelectromagnetic emissions are electrically shorted through the groundedconductive material that forms the shield, thereby reducing emissions.Likewise, when external emissions from outside the shield strike theexterior surface of the shield, a similar electrical short occurs, andthe electronic components on the module do not experience the emissions.

However, as modules continue to become smaller from miniaturization,creating effective shields that do not materially add to the size of themodule becomes more difficult. Thus, there is a need for a shield thatis inexpensive to manufacture on a large scale, does not substantiallychange the size of the module, and effectively deals with interferencecaused by unwanted electromagnetic emissions.

SUMMARY OF THE INVENTION

The present invention may be used to form one or more shields forcorresponding component areas of a given module. In one embodiment, ameta-module having circuitry for two or more modules is formed on asubstrate, which is preferably a laminated substrate. As such, thecircuitry for the different modules is initially formed on the singlemeta-module. Each module will have one or more component areas in whichthe circuitry is formed. A metallic structure is formed on or in thesubstrate for each component area to be shielded on the substrate. Inone embodiment, each metallic structure extends about all or a portionof the periphery of each of the component areas to be shielded. A singlebody, such as an overmold body, is then formed over all of the moduleson the meta-module. After the body is formed, at least a portion of themetallic structure for each component area to be shielded is exposedthrough the body by a cutting, drilling, or like operation. Next, anelectromagnetic shield material is applied to the exterior surface ofthe body of each of the component areas to be shielded and in contactwith the exposed portion of the metallic structures. The modules arethen singulated from each other to form separate modules, each of whichhaving one or more integrally shielded component areas.

Those skilled in the art will appreciate the scope of the presentinvention and realize additional aspects thereof after reading thefollowing detailed description of the preferred embodiments inassociation with the accompanying drawing figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The accompanying drawing figures incorporated in and forming a part ofthis specification illustrate several aspects of the invention, andtogether with the description serve to explain the principles of theinvention.

FIG. 1A illustrates a module having one sub-module, which is covered byan overmold body according to an example of the present invention.

FIG. 1B illustrates a cross-section of the module of FIG. 1A in which anintegrated electromagnetic shield is provided according to oneembodiment of the present invention.

FIG. 2A illustrates a module having two sub-modules, which are coveredby an overmold body according to an example of the present invention.

FIG. 2B illustrates a cross-section of the module of FIG. 2A in which anintegrated electromagnetic shield is provided according to oneembodiment of the present invention.

FIG. 3A illustrates a laminate structure having several electronicsub-module components according to the embodiment illustrated in FIGS.1A and 1B.

FIG. 3B illustrates a sub-module having a component area positioned on alaminate with an exposed metallic layer grid according to the embodimentillustrated in FIG. 3A.

FIG. 4A illustrates a laminate structure having several electronicsub-module component areas according to the embodiment illustrated inFIGS. 2A and 2B.

FIG. 4B illustrates a sub-module having a component area positioned on alaminate within an exposed metallic layer grid according to theembodiment illustrated in FIG. 4A.

FIG. 5 illustrates a strip of meta-modules according to one embodimentof the present invention.

FIG. 6 is a sectional view of a meta-module according to one embodimentof the present invention.

FIG. 7 illustrates the strip of meta-modules of FIG. 5 after a cuttingor drilling operation is provided to expose portions of the peripheralmetallic structure about each component area according to one embodimentof the present invention.

FIG. 8A illustrates a top plan view of part of the meta-module of FIG. 6with singulation lines illustrated for creating modules like thatillustrated in FIGS. 1A and 1B.

FIG. 8B illustrates a top plan view of part of the meta-module of FIG. 6with singulation lines illustrated for creating a modules like thatillustrated in FIGS. 2A and 2B.

FIG. 9 is a flow diagram illustrating a manufacturing process accordingto a first embodiment of the present invention.

FIG. 10 illustrates an exemplary module constructed according to theembodiment of FIG. 9.

FIG. 11 is a flow diagram illustrating a manufacturing process accordingto a second embodiment of the present invention.

FIG. 12 illustrates an exemplary module constructed according to theembodiment of FIG. 11.

FIGS. 13A and 13B illustrate isolated component areas to be shieldedaccording one embodiment of the present invention.

FIGS. 14A through 14D illustrate a process for providing isolatedelectromagnetic shields on a given module according to one embodiment ofthe present invention.

FIGS. 15A through 15F illustrate a process employing a sub-dicing orlike mechanical cutting process for providing an integratedelectromagnetic shield according to one embodiment of the presentinvention.

FIGS. 16A through 16D illustrate a process employing a laser cuttingprocess for providing an integrated electromagnetic shield according toone embodiment of the present invention.

FIGS. 17A through 17D illustrate a process employing a mechanical orlaser drilling process for providing an integrated electromagneticshield according to one embodiment of the present invention.

FIGS. 18A through 18F illustrate a process employing a molding form forproviding an integrated electromagnetic shield according to oneembodiment of the present invention.

FIG. 19 illustrates a meta-module without support structures underneathopenings that are cut through an overmold body according to oneembodiment of the present invention.

FIG. 20 illustrates a meta-module with support structures underneathopenings that are cut through an overmold body according to oneembodiment of the present invention.

FIG. 21 illustrates the bottom surface of a laminate that includessupport structures, such as those provided in FIG. 20.

FIG. 22 illustrates the bottom surface of a laminate on which a sealring structure is formed according to one embodiment of the presentinvention.

FIG. 23 illustrates the side view of a meta-module where a seal ringstructure is provided on the bottom side of the laminate on which themeta-module is formed according to one embodiment of the presentinvention.

FIGS. 24A through 24E illustrate a process for providing an integratedelectromagnetic shield where the metallic layer grid is built up in partusing a plating process according to one embodiment of the presentinvention.

FIGS. 25A through 25E illustrate a process for providing an integratedelectromagnetic shield where the metallic layer grid is built up in partusing surface mount structures according to one embodiment of thepresent invention.

FIGS. 26A through 26D illustrate a process for providing an integratedelectromagnetic shield where the metallic layer grid is built up in partusing surface mount structures according to another embodiment of thepresent invention.

FIGS. 27A through 27C illustrate different configurations for thesurface mount structures according to select embodiments of the presentinvention.

FIG. 28A illustrates a metallic layer grid formed from metallic studs onthe top surface of the substrate according to one embodiment of thepresent invention.

FIG. 28B illustrates a metallic layer grid formed from metallic studs ona metal trace that resides on the top surface of the substrate accordingto one embodiment of the present invention.

FIG. 29A illustrates a cross-section of a module in which an integratedelectromagnetic shield is provided according to one embodiment of thepresent invention.

FIGS. 29B through 29D illustrate cross-sections of different modules inwhich the integrated electromagnetic shield is also configured to act asa thermal path or heat sink according to one embodiment of the presentinvention.

FIGS. 30A and 30B are cross-sectional and top views, respectively, of amodule that includes field barrier structures associated with theintegrated electromagnetic shield according to one embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The embodiments set forth below represent the necessary information toenable those skilled in the art to practice the invention and illustratethe best mode of practicing the invention. Upon reading the followingdescription in light of the accompanying drawing figures, those skilledin the art will understand the concepts of the invention and willrecognize applications of these concepts not particularly addressedherein. It should be understood that these concepts and applicationsfall within the scope of the disclosure and the accompanying claims.

The present invention may be used to form one or more shields forcorresponding component areas of a given module. In one embodiment, ameta-module having circuitry for two or more modules is formed on asubstrate, which is preferably a laminated substrate. As such, thecircuitry for the different modules is initially formed on the singlemeta-module. Each module will have one or more component areas in whichthe circuitry is formed. A metallic structure is formed on or in thesubstrate for each component area to be shielded on the substrate. Themetallic structure may be formed from traces, vias, metallic layers,metallic components, plating materials, or the like, as well as anycombination thereof. In one embodiment, each metallic structure extendsabout all or a portion of the periphery of each of the component areasto be shielded. A single body, such as an overmold body, is then formedover all of the modules on the meta-module. After the body is formed, atleast a portion of the metallic structure for each component area to beshielded is exposed through the body by a cutting, drilling, or likeoperation. Next, an electromagnetic shield material is applied to theexterior surface of the body of each of the component areas to beshielded and in contact with the exposed portion of the metallicstructures. The modules are then singulated from each other to formseparate modules, each of which having one or more integrally shieldedcomponent areas.

In one embodiment, the electromagnetic shield material is provided usingan electroless plating process, which deposits a conductive seed layeron the overmold body and in contact with the exposed portions of themetallic structures. Then, an electrolytic plating process is used todeposit a second conductive layer onto the seed layer. A final layer ofa metallic material, such as nickel, is then deposited on top of thesecond conductive layer through an electrolytic plating process. Inanother embodiment, the electromagnetic shield is provided by applying aconductive epoxy or paint to the body and in contact with the exposedportion of the metallic structures. In both embodiments, the conductivelayers create an integrated electromagnetic shield for one or morecomponent areas of a module to reduce electromagnetic interference(EMI).

For the following description, the preferred embodiments of the presentinvention are described. The scope of the invention and the claims thatfollow shall not be limited to these preferred embodiments. For example,the metallic structure in the preferred embodiments is formed in wholeor in part from a metallic layer grid that resides on or in the surfaceof the substrate. Further, the metallic structure resides along all or aportion of the periphery of one or more component areas. Theseembodiment lend themselves to efficient processing; however, thoseskilled in the art will recognize that the metallic structure to whichthe integrated electromagnetic shield is connected need not reside alongthe periphery of the component area, or be part of a metallic layergrid. Importantly, the metallic structure may take virtually any form orshape, and may reside on or in the top surface of the substrate. Themetallic structure may merely be a single point along the top surface ofthe module, as well as a continuous or segmented structure that extendsalong all or a portion of the one or more component areas to beshielded. Accordingly, the metallic layer grid used in the followingembodiments to provide a metallic structure is merely provided toillustrate the preferred embodiments, and as such, shall not limit whatconstitutes a metallic structure or how a metallic structure is formedaccording to the present invention.

A module 10 is illustrated in FIGS. 1A and 1B according to oneembodiment of the present invention. The module 10 has a laminate 12,which has a metallic structure that may be formed from a metallic layergrid 14 on or in a top surface of the laminate 12 or like substrate. Asindicated above, any metallic structure may be used; however, thepreferred embodiment uses a portion of the metallic layer grid 14 toform a peripheral metallic structure. Only one section of the metalliclayer grid 14 is depicted in these figures and the peripheral metallicstructure is not separately labeled, as it is formed from the metalliclayer grid 14. The illustrated module 10 has a single component area 16that lies within the peripheral metallic structure and in whichcircuitry for the module 10 is formed. A body, such as an overmold body18, which is formed from a dielectric material, resides over thelaminate 12 and encompasses the component area 16. As depicted in FIG.1B, an electromagnetic shield 20 is integrally formed over the overmoldbody 18 and in contact with the exposed portions of the peripheralmetallic structure of the metallic layer grid 14.

A given module 10 may include any number of component areas 16 where oneor more of the component area 16 has a corresponding electromagneticshield 20. As illustrated in FIGS. 2A and 2B, two component areas 16Aand 16B are positioned in the metallic layer grid 14 such that aperipheral metallic structure is provided for each of the componentareas 16A and 16B. In certain instances, peripheral metallic structuresfor adjacent component areas 16A and 16B may share a common section ofthe metallic layer grid 14.

The illustrated module 10 has two component areas 16A and 16B, which liewithin corresponding peripheral metallic structures and in whichcircuitry (not illustrated) for the module 10 is formed. Overmold bodies18 reside over the laminate 12 and encompass the respective componentareas 16A and 16B. As depicted in FIG. 2B, electromagnetic shields 20are integrally formed over the overmold bodies 18 and in contact withthe exposed portions of the respective peripheral metallic structures ofthe metallic layer grid 14. Although the component areas 16A and 16B ofmodule 10 are illustrated as being adjacent one another, they may besubstantially separated from one another, as will be described furtherbelow.

With reference to FIG. 3A, an extended laminate structure is illustratedwherein a metallic layer grid 14 is formed on or in the top surface ofthe laminate 12. The laminate structure includes numerous componentareas 16, each of which includes the circuitry for a unique module 10,such as that depicted in FIGS. 1A and 1B where each module 10 includes asingle component area 16. The illustrated metallic layer grid 14 formedon the laminate structure is a crosshatch of metal traces, which have adefined width. Each opening of the metallic layer grid 14 forms acomponent area 16 in which circuitry of a module 10 is formed. FIG. 3Billustrates an isolated portion of the laminate structure that willultimately be used to form a module 10 having a single component area16, which is associated with a single sub-module 22. In this example, acontinuous metal trace is formed about the periphery of each componentarea 16 and represents the peripheral metallic structure for thecorresponding component area 16. The peripheral metallic structure orthe metallic layer grid 14 from which it is formed does not need to becontinuous or completely or even substantially surround the componentarea 16 as is illustrated further below. As used herein, the term“peripheral” is defined to be the outermost part or region within aprecise boundary, in particular, the boundary formed by the peripheraledge of a component area 16. Notably, this peripheral edge for a module10 having a single component area 16 resides around the peripheral edgeof the module 10. Further, the term “grid” is used merely to indicatethat a repeating pattern of metallic structures, peripheral orotherwise, is formed on the meta-module 24 because of the presence ofnumerous modules. Sections of the metallic layer grid that areassociated with different modules 10 or component areas 16 therein maybe separate from each other.

With reference to FIG. 4A, another extended laminate structure isillustrated wherein a metallic layer grid 14 is formed on the topsurface of the laminate 12. The laminate structure includes numerouscomponent areas 16A and 16B. Each pair of component areas 16A and 16Bincludes the circuitry (not illustrated) for a unique module 10, such asthat depicted in FIGS. 2A and 2B where each module 10 includes bothcomponent areas 16A and 16B. Each opening of the metallic layer grid 14forms either a component area 16A or a component area 16B in whichcircuitry of a module 10 is formed. FIG. 4B illustrates an isolatedportion of the laminate structure that will ultimately be used to form amodule 10 having two component areas 16A and 16B, which are respectivelyassociated with two sub-modules 22. In this example, a continuous metaltrace of the metallic layer grid 14 is formed about the periphery ofeach component area 16A or 16B and represents the peripheral metallicstructure for the corresponding component areas 16A and 16B. Again, theperipheral metallic structure or the metallic layer grid 14 from whichit is formed does not need to be continuous or completely surround thecomponent areas 16A or 16B.

FIG. 5 illustrates four meta-modules 24 on an extended strip of laminate12. Each meta-module 24 includes a metallic layer grid 14 and componentareas 16 (16A,16B) for numerous modules 10. An extended overmold body 18covers most of each meta-module 24, the metallic layer grid 14, and thecomponent areas 16 therein. The overmold body 18 may be a plasticdielectric material or the like, as is conventionally used forovermolding in semiconductor fabrication processes. Again, othermaterials and processes may be used to form a body providing a similarprotective encapsulation as that provided by an overmold process. Assuch, each meta-module 24 will ultimately be used to create numerousmodules 10, where each module 10 may have one or more component areas 16that correspond to sub-modules 22 depending on design requirements. Across-section of a meta-module 24 is illustrated in FIG. 6.

As illustrated, each component area 16 to be shielded for all of themodules 10 on the meta-module 24 may have a peripheral metallicstructure, which is part of the metallic layer grid 14. After the singleovermold body 18 is formed over all of the modules 10 on the meta-module24, at least a portion of the peripheral metallic structure for eachcomponent area 16 of each module 10 is exposed through the singleovermold body 18 by a cutting, drilling, or like operation, asillustrated in FIG. 7. This exposing step effectively cuts or drillsthrough the overmold body 18 to or into, but preferably not through, allor select portions of the peripheral metallic structure of the metalliclayer grid 14. Depending on design criteria, each meta-module 24 is cutor drilled such that the overmold body 18 of each component area 16 tobe shielded is distinct from one another to form sub-modules 22.Although various exposing techniques are described further below, anexemplary technique employs sub-dicing. After portions of the peripheralmetallic structure are exposed, an electromagnetic shield material isapplied to all or a portion of the exterior surface of the overmold body18 of each of the modules 10 and in contact with the exposed portion ofthe peripheral metallic structure to form an electromagnetic shield 20.The meta-module 24 is then singulated to form individual modules, whichhave one or more integrally shielded component areas, as will bedescribed in detail below.

FIG. 8A illustrates a top plan view of part of a meta-module 24 aftersub-dicing, but before separation. In this example, the metallic layergrid 14 is exposed around the periphery of each sub-module 22, whereeach sub-module 22 corresponds to a portion of the meta-module 24 for agiven component area 16. The dashed lines represent cuts to be made in asubsequent singulation process to form individual modules 10, which havea single sub-module 22. The singulation process separates the modules 10from one another. Although each module 10 is shown having a singlesub-module 22, those skilled in the art will recognize that a module 10may include any number of sub-modules 22. For example, FIG. 8Billustrates an embodiment where each module 10 will include two adjacentsub-modules 22.

FIG. 9 provides a process flow diagram detailing the steps for creatingthe module 10 that is illustrated in FIG. 10 according to one embodimentof the present invention. In particular, a meta-module 24 is formed,wherein each sub-module 22 within the meta-module 24 has a peripheralmetallic structure about the periphery of the component areas 16 to beshielded (step 100). The peripheral metallic structure is formed fromthe metallic layer grid 14.

Next, at least a portion of the peripheral metallic structure associatedwith each sub-module 22 is exposed through the overmold body 18 (step102). For example, a sub-dicing process may be employed to cut throughthe overmold body 18 of each sub-module 22 to be shielded and to themetallic layer grid 14. Other exposing techniques are described furtherbelow. At this point, a portion of the metallic layer grid 14 is exposedabout the periphery of the overmold body 18 for each sub-module 22.

The exposed surface of the overmold body 18 may be cleaned, preferablyusing a plasma cleaning process, to remove wax or other organiccompounds and materials that remain on the surfaces of the overmold body18 (step 104). The plasma cleaning process subjects the surface of theovermold body 18 to a reactive process gas, such as Argon, Oxygen,Nitrogen, Hydrogen, Carbon Tetrafluoride, Sulfur Hexafluoride, NitrogenTri-fluoride, or the like, which effectively etches away contaminants onthe exposed surface of the overmold body 18. In essence, thecontaminants are vaporized, burned, or otherwise removed from theexposed surface of the overmold body 18 when exposed to the process gas.Subsequently, the cleaned surface of the overmold body 18 for eachsub-module 22 is preferably roughened through an abrasion process, adesmear technique, or like process (step 106). In one embodiment, achemical roughening process is provided. It should be appreciated that amask (not shown) may be positioned on the underside of the laminate 12so that the processes described in the steps below do not interfere withany electrical contacts (not shown) on the bottom side of eachsub-module 22. The mask helps prevent liquids and gases from reachingthese electrical contacts, which may act as input/output contacts forthe module 10. Alternatively, a seal structure may be employed, such asthat described further below.

After roughening, an electroless plating process is performed to deposita seed layer 26 of a conductive material on top of the overmold body 18of the sub-module 22 and in contact with the exposed portions of themetallic layer grid 14 (step 108). In an exemplary embodiment, the seedlayer 26 of conductive material may be Copper (Cu), Aluminum (Al),Silver (Ag), Gold (Au), or other material as needed or desired. Anelectroless plating process is defined herein to be a chemicaldeposition of metal instead of electrical-based deposition.

An exemplary electroless plating process of Cu on a dielectric substratemay require prior deposition of a catalyst such as a palladium-tin(Pd-Sn) colloid consisting of a metallic Pd core surrounded by astabilizing layer of Sn ions. The activation step (deposition of thecolloid) is usually followed by an acceleration step (removal of excessionic tin). Adhesion of the deposit to the substrate is improved by themechanical or chemical pretreatment steps described above. Otherelectroless plating processes could also be used and are consideredwithin the scope of the present invention.

After the seed layer 26 of conductive material is created over theovermold body 18 of the sub-module 22 and in contact with the exposedportions of the metallic layer grid 14, an electrolytic plating processis performed to deposit a second layer 28 of conductive material on topof the initially deposited seed layer 26 (step 110). In an exemplaryembodiment, the second layer 28 of conductive material may be Cu, Al,Ag, Au, or other material as needed or desired. It should be appreciatedthat the exposed portions of metallic layer grid 14 are electricallycoupled to the seed layer 26, and the seed layer 26 then carries thecurrent for the electrolytic plating process.

After the second layer 28 is generated, a third layer 30 is created ontop of the second layer 28 through a second electrolytic plating process(step 112). The third layer 30 may be comparatively a poor conductor,and may be a layer of low stress nickel (Ni) or the like. Nickel servesto protect the conductive layers so that they do not tarnish, corrode,or otherwise suffer from environmental effects. Likewise, nickel maycontribute to the shielding function by absorbing electromagneticradiation.

In an exemplary embodiment, the seed layer 26, the second layer 28, andthe third layer 30 form a shield 32, which is approximately 10-50 μmthick. Greater or lesser thicknesses may also be generated. At least onemetallic coated or filled via 34 may electrically couple the peripheralmetallic structure of the metallic layer grid 14 to a ground plane 36 onthe bottom of or within the laminate 12 so that the peripheral metallicstructure of the metallic layer grid 14 and the shield 32 areelectrically grounded. The shield 32, vias 34, and ground plane 36 forman encapsulating shielding structure, which substantially encompassesthe component area 16 of each sub-module

After the electrolytic plating process of step 110, the meta-module 24is singulated to form modules 10 having two or more sub-modules 22 (step114). As used herein, the term “singulation” is defined to be theprocess wherein the individual modules 10 are separated one from theother using a cutting or like process, such that each module 10 is asingle module. Finally, the mask, which is positioned on the undersideof the strip of laminate 12, may be removed from an input/output (I/O)side 38 of the module 10 (step 116). It should be appreciated that somesteps may be rearranged in the present process. For example, the maskmay be removed prior to singulation. Likewise, if a layer 26, 28 or 30is too thick, the layer may be ground or etched down to a desiredthickness. Again, the end result of this embodiment may be a module 10having two shielded sub-modules, as illustrated in FIG. 10, although themodule 10 may be configured to have one or more sub-modules 22, wheresome or all of the sub-modules 22 have a shield 32. Although aparticular plating process is described, various electroless orelectrolytic plating techniques of any number of layers may be employed.

FIG. 11 illustrates a process flow diagram detailing the steps forcreating the module 10 that is illustrated in FIG. 12 according to oneembodiment of the present invention. As above, a meta-module 24 isinitially formed, wherein each sub-module 22 within the meta-module 24has a peripheral metallic structure about the periphery of the componentareas 16 to be shielded (step 200), and the peripheral metallicstructure is formed from the metallic layer grid 14.

Next, at least a portion of the peripheral metallic structure associatedwith each sub-module 22 is exposed through the overmold body 18 (step202). Again, a sub-dicing process may be employed to cut through theovermold body 18 of each sub-module 22 and to the metallic layer grid14, while other possible exposing techniques are described furtherbelow. At this point, a portion of the metallic layer grid 14 is exposedabout the periphery of the overmold body 18 for each sub-module 22.

The exposed surface of the overmold body 18 may be cleaned, preferablyusing a plasma cleaning process, to remove wax or other organiccompounds and materials that remain on the surface of the overmold body18 (step 204). Subsequently, the cleaned surface of the overmold body 18for each sub-module 22 may be roughened through an abrasion process, adesmear technique, or like process (step 206).

After roughening, a conductive fleck-filled epoxy 40 may be sprayed overthe overmold body 18 of each of the sub-modules 22 and in contact withthe metallic layer grid 14 (step 208). In an exemplary embodiment, theconductive fleck-filled epoxy 40 is CHO-SHIELD 610 sold by Chomerics of77 Dragon Court, Woburn, Mass. 01801. In certain embodiments, theconductive flecks of the conductive fleck-filled epoxy 40 may be Cu, Ag,a mixture of Cu and Ag, a tin/zinc (Sn/Zn) alloy, or other conductivematerial as needed or desired. Those skilled in the art will recognizeother available conductive sprays to use for shielding material. WhileCHO-SHIELD 610 has an epoxy 40 to carry the conductive flecks, othermaterials such as polyurethane, acrylic, urethane, or the like could bethe medium in which the conductive flecks are carried. Further, multiplecoats of shielding material may be applied.

One or more metallic coated or filled vias 34 may electrically couplethe metallic layer grid 14 to a ground plane 36 on the bottom of orwithin the laminate 12 so that the metallic layer grid 14 and theconductive fleck-filled epoxy 40 are electrically grounded. Theconductive fleck-filled epoxy 40, vias 34, and ground plane 36 form ashielding structure, which substantially encompasses the component area16A or 16B of each sub-module 22.

After application of the conductive fleck-filled epoxy 40, themeta-module 24 is singulated to form modules 10 having one or moresub-modules 22 (step 210). Again it should be appreciated that a maskmay be removed from an input/output side 38 of the module 10 (step 212).This mask may be removed before singulation if needed or desired.

In the above embodiments, the various component areas 16A and 16B thatare provided in a module 10, which has multiple sub-modules 22, wereillustrated as being substantially adjacent to one another. As such, aportion of the peripheral metallic structure for the adjacent componentareas 16A and 16B may be formed from the same portion of the metalliclayer grid 14. In other words, the adjacent component areas 16A and 16Bmay share a common portion of a peripheral metallic structure. However,separate component areas 16 that are located on a single module 10 maybe spaced apart from one another and may be associated with peripheralmetallic structures that are physically separate from one another,electrically isolated from one another, or both. In certain embodiments,resultant shielding structures may be isolated from one anotherelectrically, while other structures may have their structuressubstantially physically isolated from one another, wherein therespective shielding structures may be coupled to one another throughone or more dedicated traces on the surface of the laminate structure orthrough electrical connections therein.

With reference to FIG. 13A, a module 10 is illustrated as having threecomponent areas 16A, 16B, 16C. In this embodiment, assume that componentareas 16A and 16B are to be shielded, and component area 16C will not beshielded, at least according to the shielding techniques of the presentinvention. As illustrated, component areas 16A and 16B are not adjacentto one another, and are physically separated from one another on thesurface of the laminate 12 by component area 16C or other area. Withreference to FIG. 13B, the peripheral metallic structures 14A and 14B ofthe metallic layer grid 14 are provided about the component areas 16Aand 16B, respectively. Notably, the peripheral metallic structures 14Aand 14B are at least physically isolated from one another, and dependingon the electrical connections implemented on or within the laminate 12,may be electrically isolated from one another. In many embodiments, theperipheral metallic structures 14A and 14B may be ultimatelyelectrically connected to different or the same ground planes, which areprovided within the laminate structure. Such embodiments areparticularly beneficial when the electrical components in the respectivecomponent areas 16A and 16B tend to interfere with one another, such asin the case where one component area 16A includes analog electronics andthe other component area 16B includes digital electronics.

In such embodiments, all or a portion of the peripheral metallicstructures 14A and 14B are exposed through an overmold body 18 (notillustrated in FIGS. 13A and 13B). Once these portions of the peripheralmetallic structures 14A and 14B are exposed, the cleaning, roughing, andshield material application steps may be provided. If physical orelectrical isolation of the respective shields for the component areas16A and 16B is required, additional steps may be required to ensure thatthe shield material used to form the resultant electromagnetic shields20 are isolated from one another. An exemplary process to maintainseparation between the shields 20 for the respective component areas 16Aand 16B is illustrated in FIGS. 14A-14D.

With reference to FIG. 14A, a cross-section of a module 10 isillustrated at a point after portions of the peripheral metallicstructures 14A and 14B, which are associated with the component areas16A and 16B, have been exposed through the overmold body 18. Theexposing process results in openings 42 extending through the overmoldbody 18 to the peripheral metallic structures 14A and 14B. Prior toforming the different electromagnetic shields 20, a shield material mask44, such as a plating mask or a spray mask, is applied in a manner thatisolates the areas in which the respective electromagnetic shields 20are formed. As illustrated in FIG. 14B, the shield material mask 44 isprovided between the areas in which the respective electromagneticshields 20 will be formed for the respective component areas 16A and16B.

With reference to FIG. 14C, the electromagnetic shield material 46necessary to form the respective electromagnetic shields 20 is appliedover the portions of the overmold body 18 that are associated with therespective component areas 16A and 16B to form the electromagneticshields 20. Notably, the electromagnetic shield material mask 44prevents the electromagnetic shield material 46 associated with thedifferent electromagnetic shields 20 from coming into contact with eachother. As such, the electromagnetic shields 20 are formed about thecomponent areas 16A and 16B over the respective portions of the overmoldbody 18, yet remain at least physically separate from one another. In asubsequent step, the electromagnetic shield material mask 44 may beremoved, as illustrated in FIG. 14D. Notably, any number of componentareas 16 may be provided on a module 10. The resultant shielding forthese component areas 16 may be isolated or connected, wherein certainones or groups of component areas 16 may be isolated from one anotherand other ones or groups of component areas 16 may be connected to oneanother. The desired shielding requirements for the electricalcomponents provided in the respective component areas 16 should dictatesuch design decisions.

With many embodiments of the present invention, an exposing process isemployed to remove a portion of the overmold body 18 (or like body) thatis above the portion of the peripheral metallic structure to be exposed,such that the electromagnetic shield material 46 may be applied over theremaining portion of the overmold body 18 and into the openings 42 thatare created over the exposed portions of the peripheral metallicstructure. Various methods may be employed to create the openings 42through the overmold body 18, either to or partially into the exposedportions of the peripheral metallic structure. These methods includesub-dicing (mechanical cutting), laser ablation, laser drilling,mechanical drilling, plasma etching, and the like. Notably,chemical-based etching techniques may generally be considered as cuttingtechniques. Further, a molding tool or form may be provided inassociation with forming the overmold body 18, wherein all or a portionof the openings 42 are reserved using the form.

With reference to FIGS. 15A and 15B, a module 10 is illustrated prior toemploying an exposing process to create the openings 42, which areformed through the overmold body 18 to or into the portions of theperipheral metallic structure of the metallic layer grid 14 that are tobe exposed. FIG. 15A is a cross-section of the module 10, and FIG. 15Bis a top view of the module 10. As illustrated, the overmold body 18covers the metallic layer grid 14 and the component area 16, as well asthe remaining surface of the laminate structure.

With reference to FIGS. 15C and 15D, the module 10 has been subjected toa sub-dicing operation where a saw is used to form the openings 42 oversubstantially all of the peripheral metallic structure provided by themetallic layer grid 14. FIG. 15C is a cross-sectional view of the module10, and FIG. 15D is a top view of the module 10. Since the sub-dicingstep employs a saw, the openings 42 tend to take the form of trenches,which reside over the peripheral metallic structure of the metalliclayer grid 14. In certain embodiments, these trenches may extend pastthe peripheral metallic structure, which runs immediately about thecomponent area 16. Preferably, a depth-controlled cutting process isused to allow the saw to cut through the overmold body 18 to or slightlyinto the peripheral metallic structure, yet prevent the saw from cuttingall the way through the peripheral metallic structure. With reference toFIGS. 15E and 15F, the electromagnetic shield 20 is formed over theovermold body 18 and into the openings 42 as described above. FIG. 15Eprovides a cross-sectional view of the module 10 and FIG. 15F provides atop view of the module 10, after the electromagnetic shield 20 isformed.

As noted, laser ablation may also be used to form the openings 42through the overmold body 18. In general, laser ablation is the use of alaser to cut through the overmold body 18 in an analogous fashion tothat provided during a sub-dicing process. One advantage of using alaser is the ability to more precisely control the location and depth ofthe cutting operation. Since the ability to precisely control thecutting depth when forming the openings 42 is important, the ability toimmediately turn on or off a laser employed in a cutting process makeslaser ablation particularly beneficial in forming the openings 42.Notably, certain laser ablation techniques result in trapezoidaltrenches being formed for the openings 42, such as those illustrated inFIGS. 16A and 16B. FIG. 16A is a cross-section of a module 10 after theopenings 42 have been formed using laser ablation, and FIG. 16B is a topview. FIGS. 16C and 16D, which are cross-sectional and top views of themodule 10, respectively, illustrate the module 10 after formation of theelectromagnetic shield 20 over the overmold body 18 and into theopenings 42.

In addition, mechanical and laser drilling processes may be employed toform the openings 42. With reference to FIGS. 17A and 17B, which arecross-sectional and top views of the module 10, respectively, prior toformation of the electromagnetic shield 20, both types of openings 42are depicted. The opening 42 formed by mechanical drilling is referencedas 42M, and the opening formed by laser drilling is referenced as 42L.Notably, it would be unlikely that both mechanical and laser drillingwould be used to form the openings 42 for the same module 10. Thesedifferently formed openings 42M and 42L are merely illustrated torepresent the different shapes that the openings 42M and 42L may takeusing the different drilling processes.

As illustrated, openings 42M or 42L (42M/L) are drilled through theovermold body 18 to or into the peripheral metallic structure of themetallic layer grid 14 about the component area 16. The size and numberof openings 42M/L may be based on design criteria or shieldingrequirements. With reference to FIGS. 17C and 17D, the cross-sectionaland top views, respectively, of the module 10 are illustrated afterformation of the electromagnetic shield 20 over the overmold body 18 andinto the drilled openings 42M or 42L.

FIGS. 18A-18F illustrate an embodiment wherein the openings 42 arecreated using a two-step process, which employs a form to initiallycreate a form opening 48 in the overmold body 18 while the overmold body18 is being formed. Reference is now made to FIGS. 18A and 18B, whichare cross-sectional and top views, respectively, of a module 10 after anovermold body 18 has been formed. Notably, while the overmold body 18was being formed, a form was used to create the form openings 48, whichare represented as trenches over and about the component area 16 withinthe overmold body 18. After the overmold body 18 sets, the form isremoved from the overmold body 18 to leave the form opening 48. The formopening 48 in this embodiment does not extend all the way to theperipheral metallic structure provided by the metallic layer grid 14.Instead, a portion of the overmold body 18 remains between the bottom ofthe form opening 48 and the top of the peripheral metallic structure.Thus, to expose at least portions of the peripheral metallic structure,an additional step is necessary to cut or drill through the overmoldbody 18 from the bottom of the form opening 48 to the portions of theperipheral metallic structure that must be exposed. A laser ormechanical drilling or cutting process may be used to form the secondaryopening 48′ that extends from the bottom of the form opening 48 to orinto the exposed portions of the peripheral metallic structure, asillustrated in FIGS. 18C and 18D, which are cross-sectional and topviews, respectively.

With reference to FIGS. 18E and 18F, cross-sectional and top views,respectively, of the module 10 are provided after the electromagneticshield 20 is formed over the overmold body 18 and into the form opening48 and the secondary opening 48′. The form opening 48 and the secondaryopening 48′ create an overall opening 42. In all of the aboveembodiments, the electromagnetic shield 18 will extend from at least aportion of the top of the overmold body 18 through the openings 42 tothe peripheral metallic structure.

In certain embodiments, the cutting or drilling operations used to formthe openings 42 apply significant down force to the laminate 12. In manyinstances, the down force may cause the laminate 12 to flex downward,which may affect the depth of the openings 42. If the laminate 12 flexestoo much, an opening 42 may not reach the peripheral metallic structure.As such, the resultant electromagnetic shield 20 will not come intoelectrical contact with the exposed portion of the peripheral metallicstructure, which will affect the shielding performance of theelectromagnetic shield 20. If the openings 42 extend too far, all or toomuch of the peripheral metallic structure may be removed by the cuttingor drilling process, again affecting the electrical contact between theperipheral metallic structure and the electromagnetic shield, and inturn affecting the performance of the electromagnetic shield 20.

With reference to FIG. 19, a portion of a meta-module 24 is illustrated,wherein the outside edges of the meta-module 24 include a metal layer 50and a masking material 52, such as a solder mask, on the underside ofthe laminate 12. The metal layer 50 and the masking material 52effectively raise the bottom surface of the laminate 12 above aprocessing surface at the middle of the meta-module 24. Accordingly,down forces applied during cutting and drilling operations to the middleof the meta-module 24 will cause the laminate 12 to flex downward, whichmay affect the overall depth of the openings 42 that are created usingthe cutting or drilling process.

In one embodiment of the present invention, support structures 54 areprovided along the bottom surface of the laminate 12 at locations thatare substantially underneath at least part of the openings 42, asillustrated in FIG. 20. The support structures 54 may take variousforms, such as rails, pillars, or grids. As illustrated, the supportstructures 54 are formed of a metal layer 50′ and a masking material52′, in the same fashion as that used to form metal layer 50 and maskingmaterial 52. The support structures 54 need not be continuously providedunderneath the openings 42. For example, as illustrated in FIG. 21, thesupport structures 54 may be positioned at the junctions of openings 42that form a grid. As illustrated, the trench-like openings 42 willintersect one another, and beneath the intersections of thesetrench-like openings 42 will lie a support structure 54 on the opposite(bottom) side of the laminate 12. Those skilled in the art willrecognize various ways in which support structures 54 may beconstructed.

The purpose of the support structure 54 is to provide a supportmechanism to counter the downward forces that are applied to thelaminate 12 during cutting and drilling operations. Providing thesupport structures 54 prevents or significantly reduces the extent thatthe laminate 12 flexes during the cutting and drilling processes, and assuch, affords more consistent and precise cutting and drillingoperations. As a result, the openings 42 are more consistent, such thatless of the overmold material is left on those portions of theperipheral metallic structure that should be exposed, and at the sametime, ensuring that those same portions of the peripheral metallicstructure are not destroyed by cutting or drilling completely throughthem. Stabilization of the laminate 12 using the support structures 54has proven to significantly reduce the number of rejects due to cuttingor drilling too deeply, wherein the peripheral metallic structure isdestroyed, or cutting or drilling too shallowly, wherein overmoldmaterial is left on the surface of the peripheral metallic structure.

As noted, the laminate 12, and thus a meta-module 24, is carried on aprocessing platform during processing. For certain embodiments, it isbeneficial to protect the bottom surface of the laminate 12, especiallythose portions corresponding to a sub-module 22 or module 10, fromvarious gases or liquids, such as plasma etching and plating materialsthat are used to process the top surface of the meta-module 24. Withreference to FIGS. 22 and 23, one embodiment of the inventionincorporates a seal structure 56, which effectively provides a sealbetween the bottom surface of the laminate 12 and a top surface of acarrier media 62 on which the laminate 12 is carried during processing.The carrier media 62 may be a tape having an adhesive on its topsurface. In a preferred embodiment, the seal structure 56 is provided atleast in part by a metal ring 58 that is formed around an area to beprotected on the bottom of the laminate 12.

As illustrated in FIG. 22, the seal structure 56 may be provided inassociation with each meta-module 24, and effectively provide acontinuous ring about the outside periphery of the meta-module 24. Inother words, the seal structure 56 will extend about an area on thebottom surface of the laminate 12 that corresponds to all of thecomponent areas 16 for one or more meta-modules 24. The seal structure56 may be made of the same material used to form the support structure54. Regardless of material, the seal structure 56 may include a metalring 58 formed on the bottom of the laminate 12, as illustrated in FIG.23. The seal structure 56 may also include a masking material 60, suchas a solder mask, that resides on the bottom surface of the metal ring58. Whatever represents the bottom of the seal structure 56 willpreferably be adhered to the top surface of the carrier media 62sufficiently to prevent gases or liquids used during formation of thesub-modules 22 or modules 10 to substantially leak into the area beneaththe laminate 12 and within the seal structure 56. This is particularlybeneficial when numerous contact pads reside on the bottom surface ofthe laminate 12 and may be damaged, shorted, or the like if exposed tocertain liquids or gases used during fabrication. The seal structure 56need not form a complete ring. As an alternative, a spiral shape orsubstantially closed shape may suffice.

As noted above, caution should be taken to ensure that the portions ofthe peripheral metallic structure to be exposed are sufficientlyexposed, yet not destroyed, during cutting or drilling processes to formthe openings 42. In many embodiments, the metallic layer grid 14 used toform the peripheral metallic structures for the various sub-modules 22or modules 10 may be relatively thin and formed from one of the uppermetal layers of the laminate 12. As noted above, the support structures54 may be used to maintain consistent cutting and drilling processes. Inlieu of or in addition to the support structures 54, steps may be takento increase the thickness of any metallic structure, including theperipheral metallic structures formed from the metallic layer grid 14 inan effort to reduce the precision necessary to cut or drill through theovermold body 18 to or into the peripheral metallic structure to beexposed, without drilling completely through the peripheral metallicstructure.

With reference to FIGS. 24A-24E, an exemplary technique is provided toeffectively increase the thickness of the metallic layer grid 14, andthus minimize the precision necessary to effectively create the openings42 through the overmold body 18 to the peripheral metallic structures ofthe metallic layer grid 14. Initially, a first metal grid 64 is formedfrom a top metal layer of the laminate 12 using an appropriate etchingprocess, as illustrated in FIG. 24A. Subsequently, one or more platinglayers 66 are formed on top of the first metal grid 64 to form themetallic layer grid 14 using appropriate masking and plating processes,as illustrated in FIG. 24B. As described above, the overmold body 18 isformed over the peripheral metallic structures, and openings 42 are cutor drilled to or into the peripheral metallic structures, as illustratedin FIGS. 24C and 24D, respectively.

With the increased thickness of the metallic layer grid 14, the cuttingor drilling process may be configured to err on drilling deeper into themetallic layer grid 14, without excessive concern for drillingcompletely through the metallic layer grid 14. After the openings 42 areformed, the electromagnetic shield 20 may be formed over the overmoldbody 18 and into the openings 42 to the exposed portion of theperipheral metallic structure provided by the metallic layer grid 14, asillustrated in FIG. 24E. Those skilled in the art will recognize variousplating techniques to employ for providing the plating layer 66. Asnoted, multiple plating layers may be employed. Further, the sameplating process used to form the electromagnetic shield 20 may be usedto form the plating layer 66.

From the above, plating may be used to increase the relative thicknessof the overall metallic structure, such that the cutting or drillingprocess is less likely to significantly damage the metallic structure.With the plating technique, a metallic plating layer is placed over abase metallic portion, which may reside on or in the laminate 12. Thisbase metallic portion may be placed over additional metallic structuresthat are formed within the laminate 12. These metallic structures thatare formed within the laminate 12 may include metallic vias, which areeffectively holes extending into or through the laminate 12 that aresubsequently filled with metal. As such, the metallic vias and the basemetallic portion together form a metallic structure that can readilywithstand the cutting or drilling process without adversely affectingshielding performance. Notably, other metallic structures may be placedbeneath and in contact with the base metallic portion to effectivelythicken the metallic structure to which the electromagnetic shield 20 isultimately connected. These techniques, as well as the techniques thatfollow, may be employed regardless of the form or shape of the metallicstructure. For example, these thickening techniques may be employed forperipheral metallic structures that are provided in part by the metalliclayer grid 14, wherein the metallic layer grid 14 forms the basemetallic portion. Accordingly, the metallic layer grid 14 may be plated,or alternatively, placed over and in contact with vias within thelaminate 12.

Plating and the use of vias are not the only techniques for increasingthe thickness of the metallic layer grid 14. As illustrated in FIGS.25A-25E, surface mount structures 68 may be placed on the first metalgrid 64 during the same processing in which surface mount components areprovided in the component areas 16. The surface mount structures 68 arepreferably metallic and conductive. With reference to FIG. 25A, thefirst metal grid 64 is formed on the top surface of the laminate 12 asdescribed above. During the surface mount process, the surface mountstructures 68 are placed on the first metal grid 64, as illustrated inFIG. 25B, and then the overmold body 18 is applied, as illustrated inFIG. 25C. Notably, the surface mount structures 68 do not extend to thetop of the overmold body 18. As such, a cutting or drilling process isemployed to form the openings 42 that extend to or into the surfacemount structures 68, as illustrated in FIG. 25D. The electromagneticshield 20 is then formed over the overmold body 18 and to the exposedones or portions of the surface mount structures 68 through the openings42, as illustrated in FIG. 25E.

In an alternative embodiment, which is illustrated in FIGS. 26A-26D, thesurface mount structures 68 may be sized such that the top surface ofthe surface mount structure 68 is flush with the top surface of theovermold body 18. Again, the first metal grid 64 is formed on the topsurface of the laminate 12, as illustrated in FIG. 26A, and then thesurface mount structures 68 are formed on the first metal grid 64 toform the metallic layer grid 14, as illustrated in FIG. 26B. When theovermold body 18 is applied in FIG. 26C, the surface mount structures 68extend to the top surface of the overmold body 18 and are exposed. Assuch, there is no need for a cutting or drilling step to form an opening42. In effect, the cutting or drilling process is eliminated, and theelectromagnetic shield 20 may be formed along the top surface of theovermold body 18 and the surface mount structures 68, as illustrated inFIG. 26D. Although a surface mount structure 68 is illustrated, thoseskilled in the art will recognize that other plating or layeringtechniques may be used to effectively build the height of the metalliclayer grid 14 to a point that will be flush with the top surface of theovermold body 18 in an effort to avoid the need to create the openings42 extending to the top surface of the metallic layer grid 14 prior toforming the electromagnetic shield 20.

Regardless of the height of the surface mount structures 68, variousstructural configurations may be employed when building theenhanced-height metallic layer grid 14. With reference to FIG. 27A, thesurface mount structure 68 may be a solid ring, which resides on aportion of the first metal grid 64 to form the metallic layer grid 14.Alternatively, and as illustrated in FIG. 27B, numerous surface mountstructures 68 may be positioned on the first metal grid 64 to form themetallic layer grid 14. Although the first metal grid 64 is shown asbeing continuous, it may be created to correspond to the configurationsof the surface mount structure or structures 68. In FIG. 27B, thesurface mount structures 68 are shown to have a rectangular form factor,while those illustrated in FIG. 27C are shown to have a round or ovalform factor. Further, metallic structures of any type may be applied ina similar fashion outside of a typical surface mount process.

With the above embodiments, the metallic layer grid 14 may be amulti-component structure. Further, in many of these embodiments, thebase structure was the first metal grid 64, which may be continuous ordiscontinuous about the component areas 16 to be shielded. Analternative to these embodiments is provided in FIG. 28A. Asillustrated, the metallic layer grid 14, which is not specificallyreferenced, is formed from a collection of metallic studs 70, which areformed or placed along the top surface of the laminate 12. FIG. 28Aillustrates a single module 10 having three component areas 16A, 16B,and 16C; however, those skilled in the art will recognize that thearrangement of the metallic studs 70 about the overall periphery of theillustrated laminate 12 as well as about the component areas 16A and16B, may be repeated in a grid-like fashion throughout a correspondingmeta-module 24 for the different modules 10. In this example, components72 and 74 are illustrated as being in component areas 16A and 16B,respectively. Although not illustrated, component area 16C may alsoinclude electronic components. During the cutting or drilling process toexpose the metallic layer grid 14 through the overmold body 18, trenchesor holes are cut through the overmold body 18 to or into the metallicstuds 70 to be exposed. In essence, these metallic studs 70 form theperipheral metallic structure that surrounds one or more component areas16A, 16B, 16C. Component areas 16A, 16B, 16C may each have its ownelectromagnetic shield 20. Notably, the metal studs 70 are formeddirectly on the laminate 12, and not on a metal trace or layer, such asthe first metal grid 64. Instead, traces or vias within the laminate 12may be used to connect all or select ones of the metallic studs 70 to anappropriate node, such as a ground plane, for shielding purposes.

With reference to FIG. 28B, metallic studs 70 are again used to providethe metallic layer grid 14. However, the metallic studs 70 are placed ona peripheral metal trace 76. As such, various points along the metaltrace 76 may be connected through additional traces or vias to a node,such as a ground plane, for shielding purposes. In this embodiment, themetallic layer grid 14 will include the metal traces 76 for multiplemodules 10 and the metallic studs 70 that reside thereon. The cutting ordrilling process employed to expose the metallic layer grid 14 isconfigured to cut or drill to or into the metallic studs 70 that are tobe exposed. In either of the embodiments illustrated in FIGS. 28A or28B, once the selected metallic studs 70 are exposed through theovermold body 18, the electromagnetic shield 20 may be applied over theovermold body 18 and into the openings 42 to the exposed metallic studs70. From the above, those skilled in the art will recognize various waysin which to implement the metallic grid layer 14, and thus theperipheral metallic structures that are formed about all or a portion ofthe component area 16 to be shielded according to the present invention.

Notably, any metallic structure for a component area 16 may becontinuous or segmented along one or more sides of the component area16. These metallic structures need not extend completely or evensubstantially about a periphery of a component area 16. However, bettershielding performance is generally associated with more contact withmore extensive peripheral metallic structures.

The shielding techniques of the present invention may be extended toprovide functionality in addition to electromagnetic shielding. Forexample, various components residing in a component area 16 may bethermally connected to the electromagnetic shield 20, wherein theelectromagnetic shield 20 will provide a thermal path to a definedlocation or act as a heat sink itself. With reference to FIG. 29A, amodule 10 is provided with an electromagnetic shield 20 according to oneembodiment of the present invention. As illustrated, a component area 16(not referenced) includes three electronic components 78, 80, and 82.The electronic components 78 and 82 reside over and are electrically andthermally coupled to multiple thermal vias 84, which are configured todissipate heat away from the electronic components 78 and 82 through thelaminate 12 to a structure on which the module 10 will ultimately bemounted. For this example, assume that electronic component 80 does notneed such thermal vias 84. Also illustrated in FIG. 29A is anelectromagnetic shield 20, which extends over the overmold body 18 anddown to shielding vias 86, which are generally coupled to a ground planewithin the laminate 12 or on the structure to which the module 10 willultimately be mounted. In this embodiment, the electromagnetic shield 20will generally not assist in dissipating heat generated by theelectronic components 78, 80, 82.

With reference to FIG. 29B, the module 10 that was illustrated in FIG.29A has been modified such that the electromagnetic shield 20 isthermally, and perhaps electrically, coupled to the electroniccomponents 78 and 82. In this embodiment, significant portions of theovermold body 18 are exposed such that application of theelectromagnetic shield 20 will result in the electromagnetic shield 20extending to the top surfaces of the electronic components 78 and 82.Electronic component 82 relies primarily on the electromagnetic shield20 for heat dissipation, as the associated thermal vias 84 are notpresent. However, thermal vias 84 are provided for the electroniccomponent 78. As such, electronic component 78 may take advantage ofthermal vias 84 and the electromagnetic shield 20 to dissipate heat fromboth sides of the electronic component 78. The heat dissipated throughthe electromagnetic shield 20 may be primarily dissipated through theprimary structure of the electromagnetic shield 20 or passed backthrough the laminate 12 through the shielding vias 86. In either case,the shielding vias 86 may also provide an electrical path to ground forthe electromagnetic shield 20, and perhaps the electronic component 78as well.

Those skilled in the art will recognize the various options for usingthe electromagnetic shield 20 for thermal and electrical conduction.Formation of the openings above the electronic components 78 and 82 maybe provided by cutting or drilling through the overmold body 18, afterthe overmold body 18 has been applied. As such, the techniques used toprovide the openings 42 may be used to remove the portion of theovermold body 18 above the electronic components 78 and 82.Alternatively, masking techniques may be employed to prevent theovermold body 18 from being formed over these electronic components 78and 82.

The module 10 as illustrated in FIG. 29C is substantially similar tothat illustrated in FIG. 29B, with the exception that theelectromagnetic shield 20 does not extend to the electronic component78. Instead, the electromagnetic shield 20 only extends to theelectronic component 82. The thermal vias 84 are only used inassociation with the electronic component 78, and not the electroniccomponent 82. Accordingly, different electronic components 78 and 82 mayemploy different thermal paths for heat dissipation, where at least oneof the thermal paths includes the electromagnetic shield 20, which isalso used for electromagnetic shielding. Again, the electromagneticshield 20 may also provide an electrical path to ground or other nodefor the electronic component 82.

In FIGS. 29B and 29C, the portions of the electromagnetic shield 20 thatreside over the electronic components 78 and 82 extend through theovermold body 18 to the electronic components 78 and 82. The electroniccomponents 78 and 82 do not extend above the laminate 12 as far as theovermold body 18 extends above the laminate 12. As a result, openingsmust be provided above the electronic components 78 and 82 in which theelectromagnetic shield 20 extends downward to the electronic components78 and 82. In an alternative embodiment such as that illustrated in FIG.29D, the electronic components 78 and 82 may be of the same height asthe overmold body 18, such that they extend above the laminate 12 to thesame extent as the overmold body 18. Accordingly, the electroniccomponents 78 and 82 do not require openings above them within theovermold body 18 to come into contact with the electromagnetic shield20. If the electronic components 78 and 82 are not the same height asthe resulting overmold body 18, various techniques may be used toeffectively extend the height of the electronic components 78 and 82with thermally conductive material to ensure contact with theelectromagnetic shield 20.

In many instances, circuitry within a shielded area may generateelectromagnetic fields that impact other circuitry within the sameshielded area. When the circuitry creating the electromagnetic fieldscannot be separately shielded from circuitry that is sensitive toelectromagnetic fields, the overall performance of the circuitry isnegatively impacted. In one embodiment of the present invention, fieldbarrier structures 88 are formed inside the electromagnetic shield 20 inan effort to attenuate electromagnetic fields that occur inside theelectromagnetic shield 20, as illustrated in FIG. 30A. The field barrierstructures 88 may take on various shapes or forms, but will preferablyextend downward from the electromagnetic shield 20 to or toward thelaminate 12 through the overmold body 18 and perhaps any circuitryresiding in the component areas 16. As illustrated, the field barrierstructures 88 extend all the way from the electromagnetic shield 20 tothe laminate 12, and in particular to field barrier vias 90. The fieldbarrier vias 90 are coupled to the field barrier structures 88 directlyor via an appropriate trace, and extend through all or a portion of thelaminate 12 to a ground plane 92, which is illustrated in the middle ofthe laminate 12, but may reside anywhere within the laminate 12 or onthe bottom surface of the laminate 12. Notably, shield vias 94 mayextend between the ground plane 92 and the metallic layer grid 14, whichprovides the exposed portion of the metallic layer structure.Accordingly, the electromagnetic shield 20 may be connected to theground plane 92 through the metallic layer grid 14 and the shield vias94, while the field barrier structures 88 are connected to the groundplane 92 either through the field barrier vias 90 or through theelectromagnetic shield 20, the metallic layer grid 14, and the shieldvias 94. Notably, if the field barrier structures 88 do not extend allthe way to the laminate 12, an electrical connection to theelectromagnetic shield 20 is provided through the metallic layer grid 14and the shield vias 94 to the ground plane 92.

With reference to FIG. 30B, the field barrier structures 88 may beprovided anywhere within the component area 16 of the module 10. In theillustrated embodiment, electronic components 96A, 96B, and 96C residein the component area 16 and cylindrical field barrier structures 88 arepositioned in a staggered manner within the component area 16. Thedashed lines in FIG. 30B represent elements residing under thecontinuous electromagnetic shield 20 that covers most, if not all, ofthe module 10 in the illustrated embodiment.

Although FIGS. 30A and 30B illustrate substantially cylindricalconfigurations of the field barrier structures 88, those skilled in theart will recognize that the field barrier structures 88 may takevirtually any shape that may be oriented among the electronic components96A, 96B, 96C and reside within the component area 16, which is coveredby the electromagnetic shield 20. For example, the field barrierstructures 88 may form straight, angled, or curved walls or likeelements within the electromagnetic shield 20. Again, the field barrierstructures 88 may, but need not, extend completely between theelectromagnetic shield 20 to the top surface of the laminate 12. Thefield barrier structures 88 may also extend from the electromagneticshield 20 through the overmold body 18 into contact with a top portionof an electronic component 96A, 96B, 96C or simply to a point over thesecomponents or the surface of the laminate 12, without coming intocontact with anything other than the overmold body 18 and theelectromagnetic shield 20.

In one embodiment, the field barrier structures 88 are integrally formedalong with the electromagnetic shield 20. In particular, prior toapplying the electromagnetic shield 20, openings (not referenced) forthe field barrier structures 88 are formed within the overmold body 18when portions of the metallic layer grid 14 are being exposed.Preferably, the same cutting or drilling process used to expose theperipheral metallic structure of the metallic layer grid 14 is used tocreate the openings for the field barrier structures 88. After anycleaning or roughening steps, the spraying or plating processes forapplying the electromagnetic shield material for the electromagneticshield 20 will also operate to line or fill the openings to create thefield barrier structures 88 along with creating the electromagneticshield 20. As such, the field barrier structures 88 and theelectromagnetic shield 20 may form a single uniform structure, whereinthe field barrier structures 88 are electrically, thermally, andphysically connected to the electromagnetic shield 20. However, thefield barrier structures 88 need not be formed using the same process orat the same time as the electromagnetic shield 20. Different processesand different materials may be used to form the field barrier structures88 and the electromagnetic shield 20.

Preferably, the field barrier structures 88 are positioned over orwithin the component area 16 in such a way as to attenuateelectromagnetic fields emanating from one or more of the electroniccomponents 96A, 96B, 96C. Simulation or experimentation may be used forgiven embodiments, to determine the position, shape, orientation, andnumber of field barrier structures 88 to achieve desired operationalcharacteristics.

Those skilled in the art will recognize improvements and modificationsto the preferred embodiments of the present invention. All suchimprovements and modifications are considered within the scope of theconcepts disclosed herein and the claims that follow. In the claims, useof the term “certain” in association with members of a group shall meanat least one of the members of the group. All members of the group may,but need not be, considered “certain” members. Further, wherein aplurality of members of a group has a plurality of elements, onlycertain members need to have at least one element. Although acceptable,each of the certain members need not have more than one element.

1. A method of manufacturing a module comprising: providing anelectronic meta-module comprising a substrate, a plurality of componentareas on a top surface of the substrate for a plurality of modules, aplurality of electrical contacts on a bottom surface of the substrate,and a body formed from an overmold material that covers the plurality ofcomponent areas, wherein certain component areas of the plurality ofcomponent areas are associated with metallic structures that are coveredby the body, and a seal structure on the bottom surface of thesubstrate, wherein the seal structure is configured to provide a sealbetween the bottom surface of the substrate and a top surface of acarrier media on which the substrate is carried during processing;exposing at least a portion of the metallic structures associated withthe certain component areas through the body to provide a plurality ofexposed metallic structures; exposing exterior surfaces of the body to areactive process gas to clean the exterior surfaces of the body; andapplying an electromagnetic shield material over at least portions ofthe exterior surfaces of the body for each of the certain componentareas and on the plurality of exposed metallic structures to formelectromagnetic shields over the certain component areas.
 2. The methodof claim 1 wherein the reactive process gas removes contaminants on theexterior surfaces of the body.
 3. The method of claim 1 wherein thereactive process gas comprises one of a group consisting of Argon,Oxygen, Nitrogen, Hydrogen, Carbon Tetrafluoride, Sulfur Hexafluoride,and Nitrogen Tri-fluoride.
 4. The method of claim 1 wherein exposing theexterior surfaces of the body to the reactive process gas to clean theexterior surfaces of the body comprises using a plasma-based cleaningprocess to clean the exterior surfaces of the body.
 5. The method ofclaim 1 further comprising roughening the exterior surfaces of the bodyprior to applying the electromagnetic shield material.
 6. The method ofclaim 1 further comprising separating the plurality of modules of theelectronic meta-module from each other, wherein each module comprises atleast one of the certain component areas having one of theelectromagnetic shields.
 7. The method of claim 1 further comprisingseparating the plurality of modules of the electronic meta-module fromeach other, wherein each module comprises a plurality of the certaincomponent areas having the electromagnetic shields.
 8. The method ofclaim 1 wherein applying the electromagnetic shield material comprisesspraying a conductive material over the at least portions of theexterior surfaces of the body and on the plurality of exposed metallicstructures.
 9. The method of claim 1 wherein applying theelectromagnetic shield material comprises plating at least oneconductive material over the at least portions of the exterior surfacesof the body and on the plurality of exposed metallic structures.
 10. Themethod of claim 9 wherein plating the at least one conductive materialover the at least portions of the exterior surfaces of the body and onthe plurality of exposed metallic structures comprises plating a firstlayer with an electroless plating process and plating a second layerwith an electrolytic plating process.
 11. The method of claim 1 whereinproviding the electronic meta-module comprising the substrate, theplurality of component areas on the top surface of the substrate for theplurality of modules, the plurality of electrical contacts on the bottomsurface of the substrate, and the body formed from the overmold materialthat covers the plurality of component areas comprises: uniformlycovering the plurality of component areas for the plurality of moduleswith the overmold material to form the body, such that the body isinitially a single, continuous element that covers all of the pluralityof component areas prior to exposing the plurality of exposed metallicstructures.
 12. The method of claim 11 wherein uniformly covering theplurality of component areas for the plurality of modules with theovermold material to form the body, such that the body is initially thesingle, continuous element that covers the all of the plurality ofcomponent areas prior to exposing the plurality of exposed metallicstructures comprises: using an overmolding process to form the body withthe overmold material.
 13. The method of claim 11 wherein the overmoldmaterial is a dielectric material.
 14. The method of claim 1 wherein themetallic structures are located on the top surface of the substrate. 15.The method of claim 1 wherein the metallic structures associated with acertain component area of the certain component areas extendsubstantially about a periphery of the certain component area.
 16. Themethod of claim 15 wherein each metallic structure of the metallicstructures comprises a continuous metal trace on the top surface of thesubstrate.
 17. The method of claim 15 wherein each of the metallicstructures comprises a discontinuous metal trace on the top surface ofthe substrate.
 18. The method of claim 15 wherein each of the metallicstructures comprises a series of metallic structures on the top surfaceof the substrate.
 19. The method of claim 1 wherein exposing the atleast a portion of the metallic structures associated with the certaincomponent areas through the body to provide the plurality of exposedmetallic structures comprises cutting through the body at least one of:to surfaces of the plurality of exposed metallic structures; and intothe surfaces of the plurality of exposed metallic structures.
 20. Themethod of claim 1 wherein exposing the at least a portion of themetallic structures associated with the certain component areas throughthe body comprises drilling through the body at least one of: tosurfaces of the plurality of exposed metallic structures; and into thesurfaces of the plurality of exposed metallic structures.
 21. The methodof claim 1 wherein the metallic structures are part of a metallic gridthat is formed on the substrate and defines the certain component areasfor the plurality of modules.
 22. The method of claim 1 wherein theovermold material is a dielectric material.
 23. A module manufactured bya process comprising: providing an electronic meta-module comprising asubstrate, a plurality of component areas on a top surface of thesubstrate for a plurality of modules, a plurality of electrical contactson a bottom surface of the substrate, and a body formed from an overmoldmaterial that covers the plurality of component areas, wherein certaincomponent areas of the plurality of component areas are associated withmetallic structures that are covered by the body, and a seal structureon the bottom surface of the substrate, wherein the seal structure isconfigured to provide a seal between the bottom surface of the substrateand a top surface of a carrier media on which the substrate is carriedduring processing; exposing at least a portion of the metallicstructures associated with the certain component areas through the bodyto provide a plurality of exposed metallic structures; exposing exteriorsurfaces of the body to a reactive process gas to clean the exteriorsurfaces of the body; and applying an electromagnetic shield materialover at least portions of the exterior surfaces of the body for each ofthe certain component areas and on the plurality of exposed metallicstructures to form electromagnetic shields over the certain componentareas.
 24. The module manufactured by the process of claim 23 whereinthe overmold material is a dielectric material.
 25. The modulemanufactured by the process of claim 23 wherein exposing the exteriorsurfaces of the body to the reactive process gas to clean the exteriorsurfaces of the body comprises using a plasma-based cleaning process toclean the exterior surfaces of the body.
 26. The module manufactured bythe process of claim 23 further comprising roughening the exteriorsurfaces of the body prior to applying the electromagnetic shieldmaterial.
 27. The module manufactured by the process of claim 23 furthercomprising separating the plurality of modules of the electronicmeta-module from each other, wherein each module comprises at least oneof the certain component areas having one of the electromagneticshields.
 28. The module manufactured by the process of claim 23 furthercomprising separating the plurality of modules of the electronicmeta-module from each other, wherein each module comprises a pluralityof the certain component areas having the electromagnetic shields. 29.The module manufactured by the process of claim 23 wherein applying theelectromagnetic shield material comprises spraying a conductive materialover the at least portions of the exterior surfaces of the body and onthe plurality of exposed metallic structures.
 30. The modulemanufactured by the process of claim 23 wherein applying theelectromagnetic shield material comprises plating at least oneconductive material over the at least portions of the exterior surfacesof the body and on the plurality of exposed metallic structures.
 31. Themodule manufactured by the process of claim 31 wherein plating the atleast one conductive material over the at least portions of the exteriorsurfaces of the body and on the plurality of exposed metallic structurescomprises plating a first layer with an electroless plating process andplating a second layer with an electrolytic plating process.
 32. Themodule manufactured by the process of claim 23 wherein providing theelectronic meta-module comprising the substrate, the plurality ofcomponent areas on the top surface of the substrate for the plurality ofmodules, the plurality of electrical contacts on the bottom surface ofthe substrate, and the body formed from the overmold material thatcovers the plurality of component areas comprises: uniformly coveringthe plurality of component areas for the plurality of modules with theovermold material to form the body, such that the body is initially asingle, continuous element that covers all of the plurality of componentareas prior to exposing the plurality of exposed metallic structures.33. The module manufactured by the process of claim 32 wherein uniformlycovering the plurality of component areas for the plurality of moduleswith the overmold material to form the body, such that the body isinitially the single, continuous element that covers all of theplurality of component areas prior to exposing the plurality of exposedmetallic structures comprises: using an overmolding process to form thebody with the overmold material.
 34. The module manufactured by theprocess of claim 33 wherein the overmold material is a dielectricmaterial.
 35. The module manufactured by the process of claim 23 whereinthe metallic structures are located on the top surface of the substrate.36. The module manufactured by the process of claim 23 wherein themetallic structures associated with a certain component area of thecertain component areas extend substantially about a periphery of thecertain component area.
 37. The module manufactured by the process ofclaim 36 wherein each metallic structure of the metallic structurescomprises a continuous metal trace on the top surface of the substrate.38. The module manufactured by the process of claim 36 wherein each ofthe metallic structures comprises a series of metallic structures on thetop surface of the substrate.
 39. The module manufactured by the processof claim 23 wherein exposing the at least a portion of the metallicstructures associated with the certain component areas through the bodyto provide the plurality of exposed metallic structures comprisescutting through the body at least one of: to surfaces of the pluralityof exposed metallic structures; and into the surfaces of the pluralityof exposed metallic structures.
 40. The module manufactured by theprocess of claim 23 wherein the metallic structures are part of ametallic grid that is formed on the substrate and defines the certaincomponent areas for the plurality of modules.
 41. The modulemanufactured by the process of claim 23 applying the electromagneticshield material over the at least portions of the exterior surfaces ofthe body for each of the certain component areas and on the plurality ofexposed metallic structures to form the electromagnetic shields over thecertain component areas comprises: depositing a seed layer of conductivematerial on top of the body of each sub-module and in contact with theplurality of exposed metallic structures; generating a second layer ofconductive material on top of the seed layer of conductive materialthrough an electrolytic plating process; and generating a third layer ofmaterial on top of the second layer of conductive material through asecond electrolytic plating process.
 42. The module manufactured by theprocess of claim 41 wherein the seed layer of conductive material isCopper (Cu).
 43. The module manufactured by the process of claim 42wherein the second layer of conductive material is formed from Copper(Cu).
 44. The module manufactured by the process of claim 43 wherein thethird layer of conductive is formed from Nickel (Ni).
 45. The modulemanufactured by the process of claim 41 wherein the seed layer ofconductive material is deposited using a first electroless platingprocess.
 46. The module manufactured by the process of claim 45 whereinthe second layer of conductive material is deposited using anelectrolytic plating process.
 47. The module manufactured by the processof claim 46 wherein the third layer of material is deposited using asecond electrolytic plating process.
 48. The method of claim 1 whereinapplying the electromagnetic shield material over the at least portionsof the exterior surfaces of the body for each of the certain componentareas and on the plurality of exposed metallic structures to form theelectromagnetic shields over the certain component areas comprises:depositing a seed layer of conductive material on top of the body ofeach sub-module and in contact with the plurality of exposed metallicstructures; generating a second layer of conductive material on top ofthe seed layer through an electrolytic plating process; and generating athird layer of material on top of the second layer through a secondelectrolytic plating process.
 49. The method of claim 48 wherein theseed layer of conductive material is Copper (Cu).
 50. The method ofclaim 49 wherein the second layer of conductive material is formed fromCopper (Cu).
 51. The method of claim 50 wherein the third layer ofmaterial is formed from Nickel (Ni).
 52. The method of claim 48 whereinthe seed layer of conductive material is deposited using a firstelectroless plating process.
 53. The method of claim 52 wherein thesecond layer of conductive material is deposited using an electrolyticplating process.
 54. The method of claim 53 wherein the third layer ofmaterial is deposited using a second electrolytic plating process.